The Age of Supereruptions: Effects on Life

All of us, young and old, belong to an anxious generation.  The ever-present threat of nuclear war heightens our perception of risks.

A good example is how, back around the turn of the century, after media reports surfaced that Yellowstone is a supervolcano, most laypeople, including me, pictured the environmental consequences of any Yellowstone eruption as a global nuclear winter.

We can relax a little about that.  No scientific law requires supervolcanoes to always have supereruptions.

According to volcanologists, chances for another supereruption at Yellowstone are 1 in 730,000, or 0.000014%.

Nevertheless, our planet is still more likely to experience a supereruption somewhere on its surface than a large meteorite impact. (Self)

We must prepare for life during and after a supereruption.  But since one hasn’t happened in recorded history yet (Oppenheimer), how can we know what to expect?

Supereruption scenarios

While we laypeople and the media try to get psyched for the volcanic apocalypse with doomsday documentaries and fiction, researchers are using supercomputers to model supereruptions as realistically as possible.  (See, for instance, Jones and others; Mastin and others; Oppenheimer, Chapter 14; Sparks, Self, and others; Self)

Scientists have three types of data to work with:

  • Evidence of past supereruptions from the geologic record, which may include ice cores as well rock formations and deep sea drilling.
  • Well-documented “normal” eruptions, like Mount Pinatubo’s magnitude 6.1 (Oppenheimer) eruption in 1991, in which hypothetical extreme values can be substituted.
  • Fossil evidence from living beings near a supereruption.  It was signs of lung disease in plant eaters that first clued investigators in on the long-distance lethal effects from one of Yellowstone’s supereruptions.  (BBC)

Some model results, based on data from Earth’s last known ignimbrite eruption, which happened at Indonesia’s Toba volcano 74,000 years ago, show that this magnitude 8.8 (Mason and others) cataclysm could have triggered a global chill. (Rampino and Self)

The “volcanic winter” scenario is indeed one possibility . . . but there are others that are much more benign.

Continue reading The Age of Supereruptions: Effects on Life

The Age of Supereruptions: White River Fauna

I first heard of the White River Chronofauna while researching nimravids—the “false cats”—for the upcoming eBook about cat evolution.

You’ll be glad to meet these White River animals, too, if you’ve ever worried about a big natural disaster destroying the world. White River fauna not only survived a multi-million-year swarm of nearby mega-eruptions, they thrived all the time that it happened.

The group is called a chronofauna because it “maintain[ed] direct continuity through time by persistence of [its] basic ecological structure.” (E. C. Colson, quoted in Webb, 1984)

In plain English, the White River fauna were very successful for a very long time (over 10 million years).

What’s amazing about these animals—to those of us who aren’t paleontologists, anyway—is that their heyday coincided with some 20 million years of hell on Earth called the Great Ignimbrite Flareup in the Southwest. It also included the eruption of one of the world’s largest explosive large igneous provinces (LIP) in northern Mexico.

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The largest known eruption ever—La Garita—happened during the Ignimbrite Flareup.  It was 9.2 on the normally 8-point VEI scale.  Today some of the debris from that cataclysm is called the Wheeler Geologic Area in Colorado.  (Image by G. Thomas, public domain)

That faunal stability in the face of what was basically an apocalypse clashes with our popular image of a nuclear-war-scale global disaster, with mass extinctions, resulting from a single supereruption at Yellowstone or somewhere else.

But it’s true.

While this stable collection of animals thrived and multiplied out on the Great Plains, almost half of 47 supereruptions that have been recognized in Earth’s geologic record happened in Texas, New Mexico, Colorado, and Arizona. One of them, La Garita, was a 9.2 on the normally eight-point VEI scale. (Mason and others)

As if all that wasn’t enough, gigantic ash flows repaved southern Nevada and Utah over and over again, while the explosive Sierra Madre LIP eruption buried western Mexico under hundreds of thousands of cubic miles of volcanic rock.

Even the very few details of the Great Flareup that a layperson can describe are a little overwhelming, so let’s first briefly meet the animals that considered such a world normal.

The White River Chronofauna

They weren’t superanimals. They were just the weird-looking prehistoric critters that you would expect to see in a museum diorama about North American wildlife during the Eocene and Oligocene geological epochs.

That’s about halfway through the Age of Mammals, some 33 million years after the K/T extinction and roughly 33 million years before cavemen and saber-toothed “tigers.”

White River combo
Lower right image: National Park Service; Upper right: Dinictis, a nimravid (Image: Daderot, CC0 1.0); Upper left: Mesohippus, a horse (Image: Heinrich Harder, public domain); Lower left: An aquatic rhino (Image: Charles R. Knight, public domain).

Museums love this group. The richest vertebrate fossil beds in the world are where they used to live along what is now the White River in South Dakota and northern Nebraska. (Webb, 1977)

So, yes, the long-lived and abundant White River fauna lived right next door to the apocalypse. Sometimes it dropped in for a visit—a few of those ash flows reached western Nebraska. (Best and others)

Besides the cat-like nimravids, there were some very primitive-looking carnivores and herbivores in the White River complex, as well as more familiar creatures like horses (with three toes), dogs, three kinds of ancestral rhino plus the first true North American rhinoceros, the first peccaries, camels (some with horns but none with humps), and rabbits. (Prothero, 2006; Webb, 1977)

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The saber-toothed “false cat” Dinictis, chasing a horned camel.  Seriously, that’s not a cat.  (Image: Charles R. Knight, public domain)

As the group came together in the late Eocene, many of the animals were new to the continent. They were from  Asia and had migrated across the Bering land bridge. (Webb, 1977)

The land bridge was open because sea level had recently dropped. (Haq and others)  Down in Antarctica, which had been quite warm and forested during the Age of Dinosaurs and the first half of the Age of Mammals, the first glaciers to exist there in hundreds of millions of years were forming.  (Francis and others)

Meanwhile, in North America, the Asian immigrants found plenty of ecological niches open because almost a quarter of its land animals had just disappeared. (Prothero, 1994)

We’ve mentioned that the world was cooling.  That chilly spell began in the middle Eocene (Lyle and others), and now North American forests were no longer tropical evergreens, like they had been for the dinosaurs and even fairly recently.

Now, as the Eocene epoch wound down, North American forests looked more like the ones we see today in New England. There were conifers and broad-leaved trees that shed their leaves for part of the year. Such a change can be deadly when your life depends, directly or indirectly, on year-round tropical plants—many of the North America’s early primates and other primitive animals did go extinct. (Prothero, 1994; Rose)

The animals that had just migrated into North America could handle it.  Asia had subtropical forests, too, of course, but they had also known open shrublands and vegetation that was adapted to a dry climate. (Strömberg)

More change in the habitat was on the way.  After eastern Antarctica froze over at the start of the Oligocene (Zachos and others), woodland savannas and thorny forests and scrub lands appeared on North America’s Great Plains for the first time in more than 65 million years. (Webb, 1977)

And all those prehistoric herbivores and carnivores just settled down even more comfortably into their White River Chronofauna roles.

At the top of the food chain were rather wolf-like creodonts (specifically, hyaenodonts), as well as the first true dogs and some beautiful animals that you would swear were sabertoothed cats but weren’t really: these were the “false cats,” or nimravids. (Prothero, 2006)

Felids – the true cats – were strictly Old World when they first arrived. While there are some intriguing hints of early cats in North America (Hunt; Werdelin and others), none has been identified there until some six million years after the last nimravid disappeared at the end of the Oligocene. (Those feline-free years are the famous North American “cat gap.”)

So life went on for the diverse and abundant White River fauna in South Dakota and northern Nebraska. They lived there from roughly 37 million to around 21-23 million years ago. (Janis and others; Martin, 1980)

There must have been some spectacular sunsets back then, if the animals could appreciate such things as sunsets . . . or if they could even see the sky through all the volcanic haze.

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Even more spectacular than Frederic Edwin Church’s “Cotopaxi”!

Dates vary for the Great Ignimbrite Flareup, but the most intense pulses of ignimbrite eruptions in New Mexico, Colorado, and the southern Rockies—the regions closest to the White River Chronofauna—happened between 36-37 million and 21 million years ago. (Chapin and others; McDowell and McIntosh, Table 4)

In addition, the first and biggest of the ignimbrite pulses that built northern Mexico’s Sierra Madre Occidental happened from about 32 million to 28 million years ago. (Ferrari and others) In that short span of geologic time, more than 186,000 cubic miles (300,000 cubic kilometers) of tephra was erupted. (Bryan and Ferrari)

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The Sierra Madre Occidental is debris left over from gigantic explosive eruptions. (Image by Cataclasite, CC BY-SA 3.0)

Of course, Mexico is a long way from South Dakota and northern Nebraska, but you have to wonder what sort of effect the sudden addition (geologically speaking) of all that volcanic rock and gas had on global climate, on top of everything else.

But before talking about climate, we need to look at why this was happening.

The short answer is, “Plate tectonics.” It usually is, when the planet’s surface is involved.

Some of the best minds in geoscience today are still working on the longer, more detailed explanation.

The Great Ignimbrite Flareup

Okay, we have to get into plate tectonics a little bit. This is awkward, because we laypeople only understand plate tectonics intellectually.

We know, because geologists keep telling us, that Earth’s crust is broken into large plates, and that these plates jostle around. Life on the edge can be exciting, when two plate edges collide and build a mountain range, or when one plate edge slips under the other plate to form a subduction zone and then lots of volcanism happens.

But our hearts aren’t in it.

Any time of the day or night, we can look out the window at mountains and plains that appear to be fixed in time and space. We quite reasonably feel that something as solid as all that can’t move. The land is the steady foundation upon which we build our homes, our cities, and our lives.

Then an earthquake happens. It shakes up our souls as well as our physical world because we haven’t developed the sort of feeling that experts have for the very slow but inexorable movements of the Earth’s surface over geologic time.

To them, an epoch is a book page, a million years is a sentence fragment, and a hundred thousand years is merely a phrase. Stratigraphy, physics, chemistry, fossils, and advanced mathematics provide both punctuation and alphabet.

And the planet’s surface is a multidimensional Autobahn.

Well, something as vast and majestic as the Rocky Mountains can be considered eternal, given the short span of a human lifetime. But when we do that, we miss something really cool about the Rockies that can only be seen with plate tectonics.

Rockies
The Front Range, near Denver. (Image: Adam Ginsburg, CC BY 2.5)

Those mountains are sitting in the middle of the continent, nowhere near a plate edge or subduction zone. (Laramide) They didn’t just suddenly pop out of the Great Plains when a comet passed by. How did they form?

As I understand the highly-cited reports of several geologists who have investigated this, the story goes back to the early Cretaceous epoch, some 140 million years ago.  The western coast of North America looked very different. For one thing, it was one long subduction zone, including the part in California that is now the San Andreas fault.

An ocean plate was subducting under leading edge of the North American continental plate, much as one is doing in the Pacific Northwest today. As is typical in subduction zones, there was an arc of volcanoes on the overriding plate (North America, in our example). They were located about 90-125 miles (150-200 kilometers) away from the trench. (Laramide, slide 16; Zandt, slide 8D)

Volcanic_Arc_System
Image: United States Geological Survey. The USGS home page is http://www.usgs.gov.

A volcanic front like this sits above the point where the subducting slab of rock gets down far enough to melt. You get volcanoes, of course, because some of that melt reaches the surface. They’re arranged in an arc because of Earth’s curvature.

So, there was our Cretaceous subduction zone, with a volcanic arc sitting on what is now southern California and northern Mexico, carrying on normally for tens of millions of years while dinosaurs ruled the Earth and mammals kept a low but active profile in the background. There was no White River Chronofauna yet and the Great Plains weren’t a wooded savanna; where that land wasn’t drowned by an inland sea, it was covered with dense tropical rainforest. (Rose; Smithsonian, Cretaceous)

Then the volcanic arc seemed to develop a mind of its own about 100 million years ago. (Chapin and others)

It began to sweep northeastward. This unusual behavior for a line of volcanoes probably happened because the slab of subducted rock between the arc and the trench started to flatten out, moving the melting edge away from the trench. Experts in Earth science are still debating what caused that flattening. (Chapin and others; Ferrari and others)

Whatever the reason for it, the slab kept flattening as it subducted instead of dropping down at the typical angle like it had done before. As time passed, this flat section got longer and longer. The melting edge, and therefore the arc of volcanoes above it, moved farther and farther inland, away from the trench, and eventually reached the general area of modern Colorado. (Laramide, slide 16)

That volcanic arc didn’t exactly melt its way from California to Colorado; it massively deformed the rocks as it passed through. This certainly helped push up the Rocky Mountains (Zandt, slide 8E), but they also rose because, deep underground, the flat part of the slab was sort of stuck to the bottom of North America. Subduction was still going on, so the sticky slab did move, dragging against the North American plate and compressing it. (Chapin and others) There was nowhere for the overlying part of the continent to go in response to this compression but sideways and up.

Then, after it had reached Colorado, the volcanic arc headed back toward the coast. This was more unusual behavior—and it was bad news for the Southwest and northern Mexico.

Many experts think that this change of direction happened because the ongoing plate collision that had caused the west coast subduction zone in the first place slowed down. As a result, the flattened part of the subducted slab between California and Colorado started to break up and sink down into the mantle, piece by piece. The melting edge of the slab rolled back toward the trench. Besides moving the arc trench-ward, this roll-back also reduced compression on the North American plate and shut down the Laramide orogeny. (Chapin and others)

It also allowed lots of hot asthenosphere material to ooze up closer to the surface where the slab had once sat. (Chapin and others; Zandt, slide 34)

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The asthenosphere (the orange layer) doesn’t usually get close to continental crust. (Image by By NealeyS at English Wikipedia, CC BY-SA 3.0)

Sure; the extra heat from the asthenosphere melted the crust . . . somehow.  The details of exactly how that led to the production of hundreds of thousands of cubic miles of silica-rich explosive magma are controversial.

Suffice to say that there was lots of molten rock ready to go when the regional stress field completely switched over from compression to stretching as the slab continued to break and roll back. (Chapin and others)

The part of North America that had been compressed now cracked open as it was stretched. Through those weak zones, tremendous ignimbrite eruptions then surged out across the Southwest.

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Shiprock, in New Mexico, formed as a volcanic pipe when some of the rising magma came into contact with water. (Image: By Bowie Snodgrass, CC BY 2.0)

In Texas, New Mexico, Colorado, and Arizona, there were three great eruption pulses, with gaps of roughly 2 million years in between each one. An example of just part of one pulse was the eruption of almost 4,000 cubic miles (6,000 kilometers) of volcanic debris in New Mexico. At roughly the same time, at least 5,000 to 6,200 cubic miles (8,000 to 10,000 cubic kilometers) of ash and tephra blasted out of volcanic centers in Colorado. (Chapin and others)

Meanwhile, thick ash flows repeatedly swept over southern Utah and Nevada from the Sierra Nevada eastward to western Colorado. (Best and others) Think about those the next time you’re traveling through the area and see mesas and hills that resemble layer cakes. You’re really looking at stacked ignimbrite flows in cross-section. Each layer is a single eruption unit that cooled in place.

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The Bullfrog Hills in southwestern Nevada.  Names of the individual cooling units aren’t available.  (Image By Finetooth – Own work, CC BY-SA 3.0)

Some experts (Christiansen, 1979, 2001, quoted in Bryan and others) believe that each unit surged into place within just a few hours or days. That’s awesome, given the size of those layers.

But wait . . . there’s more!

As massive ash flows raged through the Southwest, one of the world’s biggest explosive LIPs also erupted in Mexico. At least a quarter million cubic miles (400,000 cubic kilometers) of volcanic material poured out of vents, fissures, or calderas to form the Sierra Madre Occidental mountains. That took more than a few hours or days, but most of it probably happened during a short span of geologic time. (Bryan and Ferrari; Ferrari and others)

And all this time the very diverse White River Chronofauna was stable in South Dakota and northern Nebraska.

Their complex group was not stagnant—the animals evolved new forms. Nimravids, for example, came up with the cheetah-like Dinaelurus crassus. This was the first known cat-like animal with “normal” teeth, i.e., relatively short, conical upper canines like the ones that all modern cats have. (Martin)

How could the White River fauna do so well during an age of supereruptions? Why didn’t those ignimbrite and LIP eruptions devastate the planet?

Surviving the apocalypse

One thing in the animals’ favor is that the ignimbrite eruptions came in pulses (McDowell and McIntosh). At least a million years of quiet passed between each pulse. Perhaps that allowed just enough time for some kind of a return to normalcy.

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OK, this is a modern leopard, but the coat pattern is primitive and some nimravids probably did shelter in trees. Imagine the saberteeth.  (Image by U.S. Fish and Wildlife Service)

But I have seen no mention that the White River animals were stressed.

They are actually the epitome of a healthy chronofauna. White River animals had no need to return to normalcy because, to them, the age of supereruptions apparently wasn’t extremely stressful.

As mentioned above, I haven’t found any expert opinions discussing this group in the context of the Great Ignimbrite Flareup. Take this for what a layperson’s opinion is worth, but I think the volcanism-dominated times were normal to this group of animals because the end dates coincide fairly closely.

The flareup quieted down some 20-24 million years ago. (Chapin and others;McDowell and McIntosh) That’s around the same time that nimravids, which are the White River animals I know some details about, went extinct in North America.

I’m so tempted to say that they were adjusted to nearby supereruptions and couldn’t handle a world without some. But I have to admit that a direct effect like that is probably not the case.

There were still nimravids in Eurasia (if you’re familiar with these gorgeous animals, I’m just talking about the first wave of nimravines). And they only lasted a few million years longer than the North American nimravids.

There must be some other reason, probably a global one, for their extinction.

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Solar radiation reduction due to relatively small volcanic eruptions. What would VEI 8 and 9 eruptions do to the planet’s climate? (Image source)

Climate is global.

And we have just seen hundreds of millions of cubic miles of rock and who knows how many gigatonnes of water vapor and gases blown up into the stratosphere, over and over again, for 20 million years.

That must have made a difference.

How did it affect Earth’s climate?

And why did animals living so close to it thrive?

Next time we’ll take a look at how Earth’s climate changed around that time and the role(s) that supereruptions might have played in those changes.

(to be continued . . .)


SOURCES:
Featured image: Prehistoric camel Poebrotherium labratum by Robert Bruce Horsfall, public domain.

Best, M. G., Christiansen, E. H., and Gromme, S. Introduction: The 36–18 Ma southern Great Basin, USA, ignimbrite province and flareup: Swarms of subduction-related supervolcanoes. Geosphere, 9(2):260–274. doi:10.1130/GES00870.1.

Bryan, S. E., Peate, I. U., Peate, D. W., Self, S., Jerram, D. A., Mawby, M. R., Marsh, J.S. (Goonie), & Miller, J. A. 2010. The largest volcanic eruptions on Earth. Earth‐Science Reviews, 102(3‐4):207‐229.

Bryan, S.E., and Ferrari, L., 2013, Large igneous provinces and silicic large igneous provinces: Progress in our understanding over the last 25 years: Geological Society of America Bulletin, 125:1053–1078. doi:10.1130/B30820.1.

Chapin, C. E., Wilks, M., and McIntosh, W. C. 2004. Space­ time patterns of Late Cretaceous to present magmatism in New Mexico—comparison with Andean volcanism and potential for future volcanism. New Mexico Bureau of Geology and Mineral Resources, Bulletin 160. Socorro, New Mexico.

Ferrari, L., Valencia-Moreno, M., and Bryan, S., 2007, Magmatism and tectonics of the Sierra Madre Occidental and its relation with the evolution of the western margin of North America, in Alaniz-Álvarez, S.A., and Nieto-Samaniego, Á.F., eds., Geology of México: Celebrating the Centenary of the Geological Society of México: Geological Society of America Special Paper 422, 1–39. doi: 10.1130/2007.2422(01).

Francis, J. E., Marenssi, S., Levy, R., Hambrey, M., Thorn, V. T., Mohr, B., Brinkhuis, H., Warnaar, J., Zachos, J., Bohaty, S., and DeConto, R. 2009. From Greenhouse to Icehouse —The Eocene/Oligocene in Antarctica. In Developments in Earth & Environmental Sciences, ed. Florindo, F. and Siegert, M. doi 10.1016/S1571-9197(08)00008-6.

Haq, B. U., Hardenbol, J., and Vail, P. R. 1988. Mesozoic and Cenozoic chronostratigraphy and cycles of sea-level change, in Wilgus, C. K., Kendall, C. G. St. C., Posamentier, H. W., Ross, C. A., and Van Wagoner, J. C., eds., Sea Level Changes- An Integrated Approach, 71-108. Tulsa: Society of Economic Paleontologists and Mineralogists Special Publication 42.

Hunt, Jr., R. M. 1998. Evolution of the aeluroid Carnivora: Diversity of the earliest aeluroids from Eurasia (Quercy, Hsanda-Gol) and the origin of felids. American Museum Novitates, Number 3252. New York: American Museum of Natural History.

Janis, C. M., J. A. Baskin, A. Berta, J. J. Flynn, G. F. Gunnell, R. M. Hunt, Jr., L. D. Martin, and K. Munthe. 1998. Carnivorous mammals. In Evolution of Tertiary Mammals of North America, ed. C. M. Janis, K. M. Scott, L. L. Jacobs, 1:73–90. Cambridge: Cambridge University Press.

Laramide (Last accessed May 7, 2016)

Lyle, M., J. Barron, Bralower. T. J., Huber, M., Olivarez Lyle, A., Ravelo, A. C., Rea, D. K., and Wilson, P. A. 2008. Pacific Ocean and Cenozoic evolution of climate. Review of Geophysics, 46, RG2002, doi:10.1029/2005RG000190.1.

Martin, L. D. 1980. Paper 287: Functional Morphology and the Evolution of Cats. Transactions of the Nebraska Academy of Sciences and Affiliated Societies. VIII:141–154.

Mason, B. G., Pyle, D. M., and Oppenheimer, C. 2004. The size and frequency of the largest explosive eruptions on Earth. Bulletin of Volcanology, 66:735–748. doi:10.1007/s00445-004-0355-9.

McDowell, F. W. and McIntosh, W. C. 2012. Timing of intense magmatic episodes in the northern and central Sierra Madre Occidental, western Mexico. Geosphere, 8(6):1505–1526. doi:10.1130/GES00792.1.

Prothero, D. R. 1994. The late Eocene-Oligocene extinctions. Annual Review Of Earth And Planetary Sciences, 22:145–165.

——— . 2006. After the Dinosaurs. Bloomington and Indianapolis : Indiana University Press.

Rose, K. D. 2006. The Beginning of the Age of Mammals. Baltimore: The Johns Hopkins University Press.

Smithsonian National Museum of Natural History. Geologic Time: The Story of a Changing Earth. n. d.  Last accessed May 7, 2016..

Strömberg, C. A. E. 2011. Evolution of Grasses and Grassland Ecosystems. Annual Reviews of Earth and Planetary Science. 2011. 39:517–44.

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Webb, S. D. 1977. A history of savanna vertebrates in the New World. Part I: North America. Annual Review of Ecology, Evolution, and Systematics, 8:355–380.

———. 1984. On two kinds of rapid faunal turnover, in Catastrophes and Earth History: The New Uniformitarianism, ed. Berggren, W.A. and Van Couvering, J.A., editors, 417–436. Princeton: Princeton University Press.

Werdelin, L., N. Yamaguchi, W. E. Johnson, and S. J. O’Brien. 2010. Phylogeny and evolution of cats (Felidae). In Biology and Conservation of Wild Felids, ed. D. W. Macdonald and A. J. Loveridge, 59–82. Oxford: Oxford University Press.

Zachos, J., Pagani, M., Sloan, L., Thomas, E., and Billups, K. 2001. Trends, Rhythms, and Aberrations in Global Climate 65 Ma to Present. Science. 292:686–693.

The Millenium Eruption of Baekdu/Changbaishan Volcano

(April 20, 2016:  The Sunday Morning Volcano comes early this week.  This volcano on the Chinese/North Korean border has been in the news.  Here is a post I made, under my other pen name, on March 2, 2014.  An update about the recent scientific study is at the bottom of the post, and I have also made a few small edits to fit the format of this blog.)

Not this millennium – the last one. More precisely, 969 A.D., give or take 20 years.

Europe was moving into the High Middle Ages, the Kingdom of Ghana in Africa was enjoying its golden age, and the Maori were settling the land now known as New Zealand, but Y1K really came in with a bang for those living around the Sea of Japan.

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Artist’s impression of initial seconds of the opening blast, with a few modern names added for orientation.  (Original image source)

It was not an effusive eruption.

In some of the videos of the volcano below, you’ll see dramatic-looking gray spires of rock lining ravines. Those are the eroded remains of massive pyroclastic flows that Changbaishan/Baekdu volcano unleashed during one of Earth’s biggest explosive eruptions since the end of the last ice age.

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The recent conversion of Plymouth, Montserrat, into a modern Pompeii was tiny by comparison.  (Image: Thorstein Boeckel)

We moderns have no frame of reference for such a thing.

Krakatau/Krakatoa blew out over 20 cubic km of material in 1883 – Baitoushan (another name for our volcano) erupted 150 cubic km in the VEI 7 Millennium Eruption.

Some of that ash covered the Korean Peninsula in a layer up to 3.2 feet (1 m) thick. The ash also traveled across the Japan Sea to drop a respectably thick layer on southern Hokkaido, Japan’s northernmost island, over 500 miles away.

Baekdu/Changbaishan has had a few more eruptions since then, the last in 1903, but much smaller ones.

Of course, the question on everybody’s mind is if and when another big one might happen.

No one has a clue as to the answer.

In geology, and particularly in volcanology, knowing what a volcano has done in the past is key to understanding its most likely threats to us here and now.

Unfortunately, people can’t even agree on Baitoushan/Changbaishan/Baekdu’s proper name, let alone adequately catalog its geologic record.

Heaven and Earth

Today the Lake of Heaven fills the caldera of this complex volcano…but Changbaishan/Baekdu’s location on the border between China and North Korea puts it smack dab in the midst of a host of worldly concerns.

The two countries have been arguing about the border here for centuries. Currently, it runs through the middle of Heaven Lake, but because of the volcano’s shape, somewhat more of the edifice is in North Korea than in China, making it off limits to most of the world’s geoscientists (until recently).

This is what a visit to the lake can look like from the Chinese side, where the volcano gets more visitors per year than Mount Fuji does in Japan, and from the North Korean side, where foreign tourists are allowed, with precautions.

Propaganda aside, Koreans (North and South) really do love this place. They, as well as China’s Manchu people, consider Baekdu/Changbaishan and its associated peaks their ancestral home.

The spiritual/psychological significance of Baitoushan today is difficult for this Westerner to comprehend.

Crater Lake, in North America, formed in a similar eruption many millennia ago and is a popular tourist site now, but it’s not as important to us as Changbaishan/Baekdu is to the Chinese and Koreans.

Here is a South Korean view:

 

The North Koreans have put the image of Paektu (their version of Baekdu) on the national emblem.

profile-and-emblem

This is the North Korean national emblem with a long shot of the volcano from a Chinese documentary so you can see the profile.  Not taking sides – please don’t yell at me.

As well, the North Koreans compose stirring music in Baekdu’s honor and tend to tell some whoppers about the volcano and their nation (for example, the ice on Tianchi Lake reportedly broke open</a> when Kim Jong Il, who literally autographed the mountain, died in December 2011).

For the Chinese, the Changbai Mountains that surround the volcano are the mythical birthplace of the founders of the Qing Dynasty, which lasted for three centuries and was replaced by the Republic of China in the 20th century, so there’s a lot of emotion invested in the volcano on that side of the border, too.

In addition, Changbaishan ginseng is a prized commodity. Logging is also profitable on the heavily forested slopes, and the Chinese have managed to establish a nature preserve there as well as a major tourist resort (as mentioned last night, South Koreans are concerned that all this is a Chinese attempt to take the entire mountain).

Here is the Chinese view, presumably waxing poetic about  Changbaishan’s beauty, though I don’t understand a word of it. There is nice camera work, though.

However, be aware, that the Millennium Eruption wasn’t the Hawaiian-style event portrayed here. Far from it!

 

Myth and Reality

Why are so many ancestral legends focused on this place, spawning the nationalism, politics and emotionalism that complicate humanity’s attempts to deal with this huge hazard?

This is just a guess, but perhaps the Millennium Eruption “reset the clock” for the people living in that region. The survivors then rebuilt their lives and societies into what developed into today’s Korea and Manchuria, the former Three Kingdoms of Korea.

hree_kingdoms_of_korea_map
The three kingdoms.  (Image by Chris 73, CC BY-SA 3.0)

Those survivors are now the honored ancestors of the Korean and Manchu people, and today the volcano that once wrought such havoc is now worshiped (either directly or secondarily through culture and politics). That’s just an outsider’s guess to explain the strong attachment many have to this volcano.

I found a Japanese-language documentary that connects the eruption of what they call Paekdusan to the collapse of the Balhae Empire at that time. I can’t make heads nor tails of what they’re saying, for the most part, but it’s presented in a very helpful visual format that’s interesting in its own right.

This four-part also has animations of the Millennium Eruption and a computer re-creation of the pre-eruption mountain. There are scientists at work, too, with nice views of fieldwork, closeups of ash particles from the eruption, etc.

Part 1:

 

In part 1, a scientist helpfully tells us in English that the Millennium Eruption removed the top kilometer of a 3500-meter-high mountain – wish I knew what the others are saying.

If you know, please do enlighten us in the comments; otherwise, those links above should help.

I think the main local players in the 10th century, as reenacted in the documentary, are the Khitans (from the general area that’s now Beijing) – that bunch of raiders in Part 1 who come in from the left – and the Balhae, who lived around the volcano and may be that large column the raiders attack.

Also, Asian reenacting is awesome!

Part 2, in which we see a U-shaped valley formed by a lahar!!!?!:

 

Part 3, in which we travel to Indonesia briefly, as well as look at possible atmospheric/climatic effects of the Millennium Eruption:

 

and Part 4.

 

Though there is no mention of this in the Wikipedia articles (I’m not an Asian history scholar) on the Three Kingdoms of Korea , the Balhae Empire, and the Goryeo-Khitan war, Yatsuzaka et al., (see source list below) do mention a link between the eruption and the empire’s collapse.

white-ash
All the names for this volcano refer to its white ash, which scientists call the Baitoushan-Tomokomai tephra.  (Image from the documentary)

Volcano Diplomacy

In the late 1990s and first decade of the 20th century, Changbaishan/Baekdu volcano showed signs of awakening.

After episodes of increased seismicity and swelling between 2002 and 2006, the volcano quieted down, but clearly magma had moved under the mountain and closer monitoring was needed.

The Chinese side of the volcano was fairly easy to access. It took some diplomacy, but in 2011 the two Koreas reached an agreement to do joint research on the North Korean side.

In 2013, geologists James Hammond, Imperial College London, and Clive Oppenheimer, University of Cambridge, began a collaborative effort with North Korean scientists to install and seismometers there.  Dr. Hammond told the BBC:

This project is not about monitoring the volcano or predicting when the eruption will happen, but is about understanding what happened during the millennium eruption and also looking at what its state is now, using geophysical techniques. This will help us understand what is driving the volcano.

Well, as of today, as far as I know, Changbaishan/Baekdu’s recent spurt of a bit of unrest has settled down and scientists are waiting for the North Koreans to take the seismograms from the equipment on the volcano’s flanks and mail them to the UK.

North Korea does not have the Internet.

Well…it’s a start.

seismicity-in-2002
Seismicity at Changbaishan/Baekdu/Baitoushan in 2002, from the Japanese documentary.

 

Update, April 20, 2016:  Here is a link to the scientific paper, “Evidence for partial melt in the crust beneath Mt. Paektu (Changbaishan), Democratic People’s Republic of Korea and China.”

As I understand it, this is the first North-Korea-based study of the Earth’s crust underneath this volcano.  It has shown that the crustal structure there is much more complex than at a distance because of the volcano’s 3.5-million-year history of eruptions.

The researchers believe that they have identified a roughly 20-kilometer-wide (roughly 12-1/2 miles) area of partial melt that is probably the source for the volcano’s historic eruptions as well as the 2002-2005 period of unrest, which probably was an episode of magma chamber recharge.

There are no warnings issued.  It’s just a little look at normal processes in an active volcano that the world has never been able to see before.

I’m not a scientist, but I think this was an enormously successful research project, accomplished with just the very basic methods and resources. That’s beautifully simple science.

It’s also very nice that a big volcano can make the news without erupting.

Here’s hoping that the volcanologists will get their wish for more research and that Paektu can be studied and monitored on its North Korean side as intensively as it is on the Chinese side.

(Edited, April 20, 2016)


Sources:

Baekdu, Korean Wikipedia article (Google translated into English)

Paektu Mountain, Wikipedia.

Changbaishan, Global Volcanism Program.

Tianchi, Wikipedia.

Top Ten Earthquakes and Volcanic Eruptions, University of Wisconsin, Green Bay.

Timeline 900-1000, Carson-Newman University.

14C Wiggle-Matching of the B-TM Tephra, Baitioushan Volcano, China/North Korea (PDF), Yatsuzuka et al., 2010.

Changbai Mountain, Wikipedia.

 

Dinosaur LIPs

The word “dinosaurs” in the title is a little misleading.  Experts say that lots of mammals were also around during the Cretaceous geologic period that ended 65 million years ago.

But mammals, even the carnivorous ones, were way down in the food chain.  Dinosaurs  owned that world . . . until an asteroid crashed the party.

Today scientists are learning that large-volume volcanism might also have contributed to the K/T extinction.  But these investigations raise as many questions as they answer.

Continue reading Dinosaur LIPs

The Socorro Magma Body

Sandhill cranes only dance during the winter at New Mexico’s wildlife refuges.

Volcanologists and other Earth scientists do their thing year-round at one particular reserve:  the Sevilleta National Wildlife Refuge, located a few miles north of the city of Socorro, New Mexico.  It’s sits some 70 miles south of Albuquerque and about 50 miles east of the National Radio Astronomy Observatory’s Very Large Array.

The boffins aren’t installing seismometers at Sevilleta to monitor birds.  They are trying to learn more about the second-largest collection of magma ever found in Earth’s continental crust.  This underground magma sits just 12 miles  below the nature reserve and other nearby areas. Continue reading The Socorro Magma Body

A more effective writing focus

After posting that Chapter Four draft here, I went back through Mauricio Antón’s Sabertooth. This time, I realized that he had written the sort of book about ancient cats that I want to write (although I am focusing on all cats): a very informative one that makes these beautiful animals come alive and shows how they lived and died during ancient terrestrial epochs that were sometimes quite tumultuous. Continue reading A more effective writing focus

If we once realize all this earth as it is, we should find ourselves in a land of miracles.. — G. K. Chesterton

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